SITE INFORMATION AND CORRESPONDENCE_FILE 1

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\s *qW 3. 2 ANALYTICAL RESULTS r. 3 . 2 . 1 Soil r During drilling of the new boreholes, MW8 , MW9, and MW10 , soil samples were collected for chemical analysis for total petroleum hydrocarbons (TPH ) and for benzene, toluene, xylenes, and ethyl- benzene ( BTXE) . The samples were analyzed by Brown and Caldwell Laboratories, using EPA Methods 8015 and 8020 as appropriate. The results (Appendix B) are shown in Table 2, along with the corresponding results for the soil samples collected for MW1 -MW3 in January 1987 ( HLA 1987 ) and for MW4-MW7 in July 1987 ( EA 1987 ) . As in the previous investigations, no hydrocarbons were detected in the soil above the ground water. However, samples collected from borehole MW8 below the water table at 28 . 5-29. 0 feet contained 3 , 200 mg/kg of total petroleum hydrocarbons. No hydrocarbons were detected in the corresponding soil samples from MW9 and MW10 . r 3 . 2 . 2 Ground Water All wells except MW6, which had floating product, were sampled, and the water was analyzed for TPH and BTXE. The results are shown in Table 2, along with earlier values for MW1 -MW7 . Samples from well MW1 indicated no detectable hydrocarbons. The wells located on the former site have TPH concentrations near or below 10 mg/L and total volatile (BTXE) concentrations below 2 . 5 mg/L. The highest concentrations of TPH ( 120 mg/L) and total BTXE r ( 56. 5 ) mg/L were detected in the water from well MW8, west of the site and next to the Shell service station (Table 2 ) ; sheen of ` free product has also been observed each time depths to liquid were gauged since the well was installed in February 1988 . In general, the concentration of hydrocarbons in the water under the site had dropped since previous sampling in July 1987 . In well r e20/73942 6